Commercial fire fighting nozzles for emitting water, such as those used on petroleum oil rigs, are typically adjustable between a jet position and a fog position. Such a nozzle may be secured to a hand-line, i.e. a hose, or to a monitor, i.e. a fixed structure. In the jet position, the nozzle emits a concentrated jet stream of water, whereas in the fog position, the nozzle emits a less concentrated, dispersed water spray. Hoses to which a nozzle is secured experience substantial backlash forces, and tend to whip violently if not restrained. The backlash is ameliorated when the nozzle is in the fog position. Upon loss of water pressure, it is desirable for the nozzle to automatically assume the fog position. Automatic return to the fog position upon loss of water pressure elminates hazardous situations that would otherwise arise if the nozzle were in the jet position when the water pressure subsequently returns.
One type of conventional nozzle has an inner tubular body that is moved longitudinally within an outer tubular body, such as the nozzle disclosed in WO 95/17926 applied for by Norfass A.S. in the name of inventor David A. Hill. This nozzle has several drawbacks. To assume the jet position, the inner body, along with a flow deflector, translates in a direction opposite of the flow of the water. Therefore, the inner body and the deflector must overcome the water pressure, making it more difficult to assume the jet position. Furthermore, this nozzle has a large number of parts, thereby adding to its complexity.